The present invention relates to metal injection machines; and particularly to an air releasing check structure of a metal injecting machine.
Injecting machines are mainly used with shaping molds for forming products. Materials are heated and then extrude and thus feed to a mold. Conventionally plastic material is used due to low melting point, small particle sizes and preferred uniformity. Moreover, in the process of storage and injection, the material has no bubble therein.
Currently, many products, for example, computer casings, uses metals as material (for example, aluminum) for replacing plastic material. However, metals have high mass and density than plastics. Moreover, the particles of the metal after melting are not so uniform as plastic particles. Thereby, conventionally, a feeding screw rod with screw threads at the middle section is used to feed material, but this will induce bubbles to be accumulated in the metal material. As a result, the surface of the product is not uniform or gaps are formed in the wall of the product.
Accordingly, the primary object of the present invention is to provide an air releasing check structure of a metal injecting machine which has a seat rod. The seat rod is installed between a rear seat at a front section of a feeding screw rod and the extruding head at the front end in the feeding screw rod; a periphery of the seat rod being enclosed by a check toggle. If the material to be injected from the injecting mouth has bubbles so that it is not extruded effectively, the bubbles will flow to the exhausting groove of the check toggle. Then the bubble flows through an upper side of the contact surfaces of the first and second chamfered surfaces for draining out. Thereby, the bubbles in the material is vented out so that the material becomes dense. When the material becomes dense because of high pressure, the material flows to the toggle from the pressure releasing holes. For a longer time, the pressure of material will be greater than the force for buckling of the elastic toggles so that the toggles expand. As a result, a periphery of the toggle will press against a wall of the feeding groove; then the elastic toggle will further isolate the exhausting groove. Thereby, the material moves forwards to be injected from the extruding head.